When manufacturing electrical circuit devices such as semiconductor integrated circuit devices, it is inspected during or after a process of manufacturing devices and before a packaging process whether the entire or partial electric properties of devices are formed to be identical to a design thereof.
A device used in such inspections is a probe station, and a probe card is installed in the probe station. The probe card transfers all kinds of electric signals of the probe station to pads of devices formed on a semiconductor wafer, which are objects of measurement.
The probe card is formed of two parts. One is a circuit board structurally supporting a probe and including a circuit connecting the probe station and the probe and formed on the board. Another is a probe installed on the board, which electrically connects the circuit board to pads of a device for measurement.
A device for measurement is put on a chuck and the chuck moves in a direction of X and Y axes in such a way that a probe of a probe card are to be matched with pads of the device for measurement. The chuck moves in a direction of Z axis in such a way that the probe is in contact with the pads of the device for measurement.
After that, an electric signal generated in the probe station is transferred to the circuit board of the probe card, passes through the probe via an electric line connecting the circuit board to an end of the probe, and transmitted to the device for measurement, thereby performing a test.
Recently, electrical contact points of semiconductor devices become very smaller in such a way that, in general, several tens to several hundreds of pads for electrical contact points are arranged with a pitch less than several ten micrometers therebetween per a device.
Recently, since probe cards measure several devices at the same time, there are required a large numbers of probes. Also, due to a very small pitch between pads of a device, a pitch between probes in contact with pads is also very small. However, it is required a high degree of process technology to embody probe blocks with a fine pitch and there are many problems such as costs and time for embodying.
FIG. 1 is a configuration view illustrating a semiconductor chip 100 with a staggered pad arrangement.
In a chip having an in-line pad structure, pads are arranged in a row. In the semi-conductor chip 100 with a staggered pad arrangement, pads P11 and P12 are arranged in a double row in a series of zigzags to provide largest number of pads P11 and P12 in a small size.
FIG. 2 is a view illustrating a probe block for test, overlapping the semiconductor chip 100 of FIG. 1.
Referring to FIG. 2, there are shown pads arranged in one side of the semiconductor chip 100 and guide holes where probes (not shown) of a probe block (not shown) are overlapped upon the pads.
In FIG. 2, pads are arranged in a series of zigzags to increase a degree of integration of the pads in the semiconductor chip with a staggered pad arrangement and there are shown a connection structure of a first pad P11 in a first row and a first pad P21 in a second row.
There are shown an upper hole where a first contact portion of the probe is inserted in and protruded to be in contact with the first pad P11 of the first row, a lower hole HD11 where a second contact portion of the probe is inserted in and protruded to receive a test signal from the opposite of the upper hole HU11, and a center hole HC1 where a beam connecting the first contact portion to the second contact portion.
Also, there is shown a probe having the same structure to be in contact with the first pad P21 of the second row. That is, there are shown an upper hole HU21, a lower hole HD21, and a center hole HC2 where the probe for being in contact with the first pad P21 of the second row is inserted in.
In contact points C11 and C21, the respective probes corresponding to the first pad P11 in the first row and the first pad P21 in the second row are in contact therewith.
When a pitch between neighboring pads in an in-line pad structure in which pads are arranged in a row is 50 micrometers, either of a pitch between probes in contact with the respective pads or a pitch between holes where probes are inserted in is also 50 micrometers.
However, in the semiconductor chip with the staggered pad arrangement in FIG. 2, since pads crisscross one another, a pitch between the pad P11 and the pad P21 is half that of the in-line pad structure, that is 25 micrometers.
Accordingly, pitches between holes such as upper holes, lower holes, and a center hole where the probes contacting with the pad P11 and P21, respectively, are inserted are determined to be 25 micrometers and widths of respective holes become very smaller to 10 micrometers, which makes manufacturing difficult. Also, a depth D of a wall between holes is very small, which makes a structure thereof become weak.
FIG. 3 is a three-dimensional perspective view illustrating a probe block for the semiconductor chip with a staggered pad arrangement of FIG. 2. FIG. 4 is a top view illustrating the probe block of FIG. 3.
As described above with reference to FIG. 2, to test pads P11 and P21 arranged in a series of zigzags, upper holes HU11 and HU21 formed on a guide of the probe block are formed in a series of zigzags. Also, probes PB1 and PB2 are inserted in the upper holes HU11 and HU21, respectively. In FIG. 3, the upper hole HU21, a center hole HC2, and a lower hole HD2 where the probe PB2 is inserted.
FIG. 4 is a top view illustrating the probe block of FIG. 3, in which it may be known that holes where respective probes are inserted are formed in a series of zigzags, identical to the arrangement of pads.
When probes to be in contact with pads arranged inside of two rows are arranged inside and probes to be in contact with pads arranged outside are arranged outside to increase a pitch between holes where a probe is inserted, in an area 40 of FIG. 4, it is impossible to form a probe block due to an overlap between probes in contact with pads arranged in a top in a horizontal direction and probes in contact with pads arranged vertically.
Accordingly, when holes where probes are inserted in are formed on a guide as shown in FIG. 4, it becomes difficult to manufacture probe blocks for testing semi-conductor chips with a staggered pad structure or a structure in which pads are arranged in a plurality of rows, due to decreased pitch of holes where probes are inserted in.